The stresses of caring fora relative with Alzheimer's Disease (AD) can have important adverse effects on caregivers. Evidence from the study funded by the current grant showed that caregivers, particularly spouses, were at risk for syndromal depression, nd caregivers had poorer immune function on qualitative assays and a greater incidence or respiratory tract infections than similar older adults without caregiving responsibilities. Moreover, caregivers showed declines on qualitative immunological assays in the second year, while controls were stable. In order to better understand the longer-term mental and physical health consequences of caregiver for AD victims, this renewal proposes the continuation of annual data collection including psychological data, blood samples for immunological and nutritional analyses, and health status information from 140 AD spousal caregivers for five years. The mental and physical health impact of caregiving with information collected at the same intervals from 100 sociodemographically-comparable control subjects who do not have caregiving responsibilities. Analyses of caregiver data will help to identify the bets predictors of psychological and immunological functioning. The results of these analyses will provide the basis for constructing models that specify key mediators of caregivers' emotional and physical health. A better understanding of these key mediators is essential for both the identification of at-risk caregivers, and for the design of effective intervention programs.